The Conservative Party will get rid of Mrs Thatcher in about three years' time and Lord Carrington will probably become party leader, according to Sir Harold Wilson in a television interview to be screened tonight.

Speaking on the BBC Panorama programme, Sir Harold says that Mrs Thatcher will be consigned to Tory mythology. "If they (the Tories) decide they're going to lose the next election with her there, she'll be ditched and it will be as though she's never been. She'll become a non-person."

He describes Mrs Thatcher as "the best man" the Tories have got and praises her for her success over Rhodesia, attributing her achievement to Lord Carrington, the Foreign Secretary. "I think he would be a very formidable leader. I think he would take an awful lot of beating."

On the Labour Party leadership, Sir Harold says he voted for Denis Healey in the first ballot but would not reveal his second ballot choice. He thought the Labour Party conference at Blackpool was "a shambles", especially with the "tomfoolery" about an electoral college to choose a future leader.

"I think the right people to elect not only the leader of the (Labour) party but the future Prime Minister are the Members of Parliament who for most part, in my view, carry the full support and confidence of the Labour voters."

On the question of Tony Benn as a possible leader, Sir Harold says: "I don't think people will really have a lot of time for him."

Sir Harold warns Labour's new leader, Michael Foot, not to let his personal views get in the way of running the party. "He must not impose a narrow sectarian set of policies upon the party, and I am thinking particularly about, for example, leaving the Common Market."

On the future of Western politics, with America in mind, Sir Harold says of defeated President Carter: "I didn't think he was up to the job . . . so I wasn't sorry when he went."

As for President-elect Ronald Reagan: "We can only hope and pray that he's going to be a good President. So far, he hasn't said much or done much to suggest that he won't."

Grant suit

Hollywood star and businessman Cary Grant has filed a slander suit seeking $10 million in damages from comedian Chevy Chase, alleging Mr Chase alluded to him as a homosexual. Mr Grant, aged 76, whose four marriages ended in divorce, maintained in his suit that Mr Chase made the reference on a television show.